Terrestrial farming has existed for millenia. However, it has only been in the last few decades that alternative plant growing systems have been widely adopted; such systems include hydroponics, aquaponics and aeroponics. These alternative growing systems have attempted to alleviate the many issues inherent in terrestrial-based farming. For instance, terrestrial farming requires a large area of arable land, abundant quantities of water, and in many commercial farming operations, large amounts of chemicals, including herbicides, pesticides and fungicides. Terrestrial farming is also subject to the vagaries of nature, including devastation caused by floods, droughts, fires and frosts/freezes. Each of the exemplary alternative systems seeks to address one or more of these drawbacks of terrestrial farming.
As implied by its name, hydroponics involves growing plants within a water medium. That is, plant roots may be suspended directly within a pool of water or may be supported by an inert medium, such as perlite or gravel which is saturated with water. The plant roots are exposed to a nutrient-rich solution to promote plant growth. A number of hydroponic techniques have been developed, including continuous-flow hydroponics wherein the nutrient solution slowly flows past the plant roots; drip hydroponics where nutrient solution is pumped from a reservoir to slowly drip onto the top surface of the inert medium and flow past the roots before being recycled in the nutrient reservoir; ebb and flow hydroponics wherein the plant container is continuously flooded with nutrient solution and then allowed to drain; and deep water culture wherein the plant roots are suspended within the water/nutrient solution while an air pump bubbles oxygen into the solution for root uptake. Each of these systems provides for closed-environment growing thereby reducing the need for harmful chemicals. However, hydroponics remains a water-intensive alternative to terrestrial farming.
Similar to hydroponics is aquaponics wherein a hydroponics plant growing system is symbiotically coupled to an aquaculture system used for raising aquatic animals in a closed system. Aquaponics utilizes the water that used to cultivate aquatic animals as the nutrient feedstock for the plants being grown in the hydroponic system. That is, animals in the aquaculture pool produce nitrogen-rich excretions which will eventually poison the water. However, this nitrogen-rich water is cycled to the hydroponic system wherein the plants use the nitrogen as plant nutrients, thus removing the nitrogen from the water. The water is then recycled to the aquaculture system for use in cultivating the aquatic animals. While aquaponics may symbiotically couple hydroponics with aquaculture, aquaponics, by its nature, requires a vast amount of water to grow both the animals and the plants. Nevertheless, aquaponics is a viable alternative to terrestrial farming.
Aeroponics is a process of growing plants using air as the growth medium. In an aeroponic system, the plant is suspended such that its stems, leaves and any fruit grow in a vegetative zone above the suspension medium. The roots dangle below the suspension medium in an area commonly referred to as a root zone. The dangling roots receive water and other nutrients through an atomized spray of nutrient-laden water commonly referred to as “nutrient tea.”
Aeroponics has been known in the art for decades and is generally either a low pressure system or a high pressure system. High pressure aeroponic systems offer numerous benefits over low pressure systems such that high pressure systems are nearly exclusively utilized within large commercial systems. Additionally, as the price and availability of system components have become more amenable to hobbyists, high pressure systems have increasingly become adopted by home gardeners.
In operation, high pressure aeroponic systems pressurize the nutrient tea and spray it through an atomizer or mister that aerosolizes the tea directly onto the root zone. In this manner, aeroponics offers significant advantages over hydroponics (which utilizes a liquid growing medium) and geoponics (which uses soil or other aggregate material as a growing medium). Specifically, by having the roots suspended within air, aeroponic systems increase the availability to oxygen (O2) and carbon dioxide (CO2) to the plant roots. Both atmospheric gases are vital to plant growth such that aeroponically grown plants grow faster and healthier than other systems.
While aeroponic systems provide numerous benefits over other growing systems, there still exist drawbacks with current aeroponic systems. Among these issues is poor crop reliability. Specifically, present aeroponic systems utilize spray systems which provide water droplets either from the bottom up or from the side wall of the aeroponic container. The spray pattern of the misters may be interfered with and degraded by the growing root mass. That is, current systems utilize atomizers or other misters which inefficiently spray the nutrient tea such that the root zone experiences regions of “wet” and “dry” zones. Wet zones receive too much nutrient tea such that gas exchange (O2 and/or CO2) is hindered, while dry zones do not receive sufficient nutrient tea (if any at all) such that nutrient uptake by the roots is inadequate. In either case, wet zones and dry zones negatively affect plant growth and fruit production.
Within each of the alternative growing methods described above, a further deficiency in the art is the inability to efficiently add, remove, modify or otherwise manipulate a modular growing system. While current systems known in the art have been designed to be expanded, this expansion is highly cumbersome and directly impacts plant growth and productivity. For instance, high pressure aeroponic systems deliver nutrient tea through atomizers or other misters operating at pressures in excess of 75-80 psi. Currently available aeroponic systems require operators to turn off the pressure system to the entire system when expanding or otherwise manipulating or repairing a single aeroponic unit or individual component thereof (i.e., replacing a clogged atomizer). Indeed, some systems even require re-priming of the pump(s) before the pressure system is brought back online.
Finally, present aeroponic systems employ control systems that are not integrated for central control. These systems often contain analog controllers. Thus, the availability for process automation, automatic system error detections (e.g., insufficient spray pressure, individual atomizer malfunction, etc.) is not possible with currently available systems.
Accordingly, what is needed is a “plug-and-play” system which allows for efficient maintenance and/or expansion of individual units within the system without interrupting or otherwise disturbing the operation of other individual aeroponic units. What is further needed is an aeroponic system having atomizers/misters and unit constructions which minimize the occurrence of wet or dry zones within the root zone. What is further needed is an automated digital control system that runs preprogrammed spray operations; monitors and controls the temperature, humidity (i.e., activation of the misters), CO2 levels, light quality, light intensity, and other suitable plant growth parameters; and initiates alarms in the event of high or low sensor readings, pump failure, pressure loss, water loss, power failure or the occurrence of any other monitored process variable. The present invention fulfills these and other needs.